When I search for text on my Vibe site, I get some results from .doc or .xls files, but not form others. I tried to re-index a single folder to test the results (log file shows the the indexing was done with no errors), but after re-indexing that folder, content was still not found for a text search. Are there some limitations with the indexing or some re-configuration I need to do as the size of my site increases?